Answer to Question #7991 Submitted to "Ask the Experts"

Category: Nuclear Medicine Patient Issues

The following question was answered by an expert in the appropriate field:

Q

My father had a test recently where he digested a radioactive substance and then was given an MRI (magnetic resonance image) and a CAT (compuerized axial tomography) scan. He was told by the radiologist that he could not hold my child but was otherwise safe. Is this true, or should my child not come in contact with him for a certain amount of time?

A

No radioactive material is administered for MRI scans or computerized tomography (CT or CAT) scans. Both exams usually include an injection or the drinking of a contrast solution. The contrast solution for CT scans contains nonradioactive iodine; the staff ask patients if they are allergic to iodine so that they can be medicated against an allergic reaction. Sometimes people think that they are being administered radioactive iodine.

The contrast solution used in MRI is not radioactive. But the word "gadolinium" sounds radioactive. MRI makes images like CT scans, but they do not use radiation to make the image.

You can get the records or ask the doctor again if there were any nuclear medicine exams involved and what the material was that was given to your father. Most nuclear medicine injections decay rapidly so there is little left the next day from decay and by elimination of the material from the body by urinating.

Marcia Hartman, MS 

Ask the Experts is posting answers using only SI (the International System of Units) in accordance with international practice. To convert these to traditional units we have prepared a conversion table. You can also view a diagram to help put the radiation information presented in this question and answer in perspective. Explanations of radiation terms can be found here.
Answer posted on 26 January 2009. The information posted on this web page is intended as general reference information only. Specific facts and circumstances may affect the applicability of concepts, materials, and information described herein. The information provided is not a substitute for professional advice and should not be relied upon in the absence of such professional advice. To the best of our knowledge, answers are correct at the time they are posted. Be advised that over time, requirements could change, new data could be made available, and Internet links could change, affecting the correctness of the answers. Answers are the professional opinions of the expert responding to each question; they do not necessarily represent the position of the Health Physics Society.